1. Field of the Invention
The present invention relates to a cathode material in which a plurality of cathode active materials are mixed and a battery using the cathode material.
2. Description of the Related Art
In recent years, portable electronic devices such as a notebook personal computer, a combination camera (videotape recorder), and a mobile phone have been introduced one after another, and their size and weight have been reduced. Accordingly, secondary batteries as a portable power source have been highlighted, and active researches for obtaining a higher energy density have been implemented. Under such circumstances, as a secondary battery having a high energy density, lithium ion secondary batteries have been in practical use.
In such lithium ion secondary batteries, for example, it is proposed that in order to improve the battery characteristics such as a capacity and cycle characteristics, as a cathode active material, two kinds of complex oxides containing lithium (Li), manganese (Mn), nickel (Ni) or cobalt (Co) and the like are mixed (for example, refer to Japanese Unexamined Patent Application Publication No. 2003-173776).